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Switch the 85xx defconfigs from the soon to be removed legacy ide
driver to libata.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200924041310.520970-1-hch@lst.de
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In commit 61f879d97ce4 ("powerpc/pseries: Detect secure and trusted
boot state of the system.") we taught the kernel how to understand the
secure-boot parameters used by a pseries guest.
However, CONFIG_PPC_SECURE_BOOT still requires PowerNV. I didn't
catch this because pseries_le_defconfig includes support for
PowerNV and so everything still worked. Indeed, most configs will.
Nonetheless, technically PPC_SECURE_BOOT doesn't require PowerNV
any more.
The secure variables support (PPC_SECVAR_SYSFS) doesn't do anything
on pSeries yet, but I don't think it's worth adding a new condition -
at some stage we'll want to add a backend for pSeries anyway.
Fixes: 61f879d97ce4 ("powerpc/pseries: Detect secure and trusted boot state of the system.")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200924014922.172914-1-dja@axtens.net
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Build the kernel with 'make C=2':
arch/powerpc/platforms/pseries/papr_scm.c:825:1: warning: symbol
'dev_attr_perf_stats' was not declared. Should it be static?
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918085951.44983-1-wangwensheng4@huawei.com
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This is not used by 64s.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-5-npiggin@gmail.com
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Since the assembly soft-masking code was moved to 64e specific, there
are some 64s specific interrupt types still there. Remove them.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-4-npiggin@gmail.com
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This is not used anywhere.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-3-npiggin@gmail.com
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Replayed interrupts get an "artificial" struct pt_regs constructed to
pass to interrupt handler functions. This did not get the softe field
set correctly, it's as though the interrupt has hit while irqs are
disabled. It should be IRQS_ENABLED.
This is possibly harmless, asynchronous handlers should not be testing
if irqs were disabled, but it might be possible for example some code
is shared with synchronous or NMI handlers, and it makes more sense if
debug output looks at this.
Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-2-npiggin@gmail.com
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Prior to commit 3282a3da25bd ("powerpc/64: Implement soft interrupt
replay in C"), replayed interrupts returned by the regular interrupt
exit code, which performs preemption in case an interrupt had set
need_resched.
This logic was missed by the conversion. Adding preempt_disable/enable
around the interrupt replay and final irq enable will reschedule if
needed.
Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200915114650.3980244-1-npiggin@gmail.com
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The hypervisor interface has defined branch prediction security bits for
handling the link stack. Wire them up.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200825075612.224656-1-npiggin@gmail.com
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The copy buffer is implemented as a real address in the nest which is
translated from EA by copy, and used for memory access by paste. This
requires that it be invalidated by TLB invalidation.
TLBIE does invalidate the copy buffer, but TLBIEL does not. Add
cp_abort to the tlbiel sequence.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fixup whitespace and comment formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916030234.4110379-2-npiggin@gmail.com
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Having cputable.h include mce.h means it pulls in a bunch of low level
headers (e.g., synch.h) which then can't use CPU_FTR_ definitions.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916030234.4110379-1-npiggin@gmail.com
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Every error log reported by OPAL is exported to userspace through a
sysfs interface and notified using kobject_uevent(). The userspace
daemon (opal_errd) then reads the error log and acknowledges the error
log is saved safely to disk. Once acknowledged the kernel removes the
respective sysfs file entry causing respective resources to be
released including kobject.
However it's possible the userspace daemon may already be scanning
elog entries when a new sysfs elog entry is created by the kernel.
User daemon may read this new entry and ack it even before kernel can
notify userspace about it through kobject_uevent() call. If that
happens then we have a potential race between
elog_ack_store->kobject_put() and kobject_uevent which can lead to
use-after-free of a kernfs object resulting in a kernel crash. eg:
BUG: Unable to handle kernel data access on read at 0x6b6b6b6b6b6b6bfb
Faulting instruction address: 0xc0000000008ff2a0
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
CPU: 27 PID: 805 Comm: irq/29-opal-elo Not tainted 5.9.0-rc2-gcc-8.2.0-00214-g6f56a67bcbb5-dirty #363
...
NIP kobject_uevent_env+0xa0/0x910
LR elog_event+0x1f4/0x2d0
Call Trace:
0x5deadbeef0000122 (unreliable)
elog_event+0x1f4/0x2d0
irq_thread_fn+0x4c/0xc0
irq_thread+0x1c0/0x2b0
kthread+0x1c4/0x1d0
ret_from_kernel_thread+0x5c/0x6c
This patch fixes this race by protecting the sysfs file
creation/notification by holding a reference count on kobject until we
safely send kobject_uevent().
The function create_elog_obj() returns the elog object which if used
by caller function will end up in use-after-free problem again.
However, the return value of create_elog_obj() function isn't being
used today and there is no need as well. Hence change it to return
void to make this fix complete.
Fixes: 774fea1a38c6 ("powerpc/powernv: Read OPAL error log and export it through sysfs")
Cc: stable@vger.kernel.org # v3.15+
Reported-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Rework the logic to use a single return, reword comments, add oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201006122051.190176-1-mpe@ellerman.id.au
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This fixes a compile error with W=1.
CC arch/powerpc/kernel/traps.o
../arch/powerpc/kernel/traps.c:1663:6: error: no previous prototype for ‘stack_overflow_exception’ [-Werror=missing-prototypes]
void stack_overflow_exception(struct pt_regs *regs)
^~~~~~~~~~~~~~~~~~~~~~~~
Fixes: 3978eb78517c ("powerpc/32: Add early stack overflow detection with VMAP stack.")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-8-clg@kaod.org
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This fixes a compile error with W=1.
CC arch/powerpc/sysdev/xive/common.o
../arch/powerpc/sysdev/xive/common.c:1568:6: error: no previous prototype for ‘xive_debug_show_cpu’ [-Werror=missing-prototypes]
void xive_debug_show_cpu(struct seq_file *m, int cpu)
^~~~~~~~~~~~~~~~~~~
../arch/powerpc/sysdev/xive/common.c:1602:6: error: no previous prototype for ‘xive_debug_show_irq’ [-Werror=missing-prototypes]
void xive_debug_show_irq(struct seq_file *m, u32 hw_irq, struct irq_data *d)
^~~~~~~~~~~~~~~~~~~
Fixes: 930914b7d528 ("powerpc/xive: Add a debugfs file to dump internal XIVE state")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-5-clg@kaod.org
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The check should be performed by the caller. This fixes a compile
error with W=1.
../arch/powerpc/lib/sstep.c: In function ‘mlsd_8lsd_ea’:
../arch/powerpc/lib/sstep.c:225:3: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
; /* Invalid form. Should already be checked for by caller! */
^
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-4-clg@kaod.org
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This fixes a compile error with W=1.
arch/powerpc/kernel/sysfs.c: In function ‘sysfs_create_dscr_default’:
arch/powerpc/kernel/sysfs.c:228:7: error: variable ‘err’ set but not used [-Werror=unused-but-set-variable]
int err = 0;
^~~
cc1: all warnings being treated as errors
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914211007.2285999-2-clg@kaod.org
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The logic of the warn output is incorrect. The two args should be
exchanged.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916062129.190864-1-miaoqinglang@huawei.com
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Use for_each_child_of_node() macro instead of open coding it.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916062138.191188-1-miaoqinglang@huawei.com
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Use for_each_child_of_node() macro instead of open coding it.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916062125.190729-1-miaoqinglang@huawei.com
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Use for_each_child_of_node() macro instead of open coding it.
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916062122.190586-1-miaoqinglang@huawei.com
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It's possible to enable CONFIG_PPC_EARLY_DEBUG_BOOTX for a pseries
kernel (maybe it shouldn't be), which is then booted with qemu/slof.
But if you do that the kernel crashes in draw_byte(), with a DAR
pointing somewhere near INT_MAX.
Adding some debug to prom_init we see that we're not able to read the
"address" property from OF, so we're just using whatever junk value
was on the stack.
So check the properties can be read properly from OF, if not we bail
out before initialising btext, which avoids the crash.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Link: https://lore.kernel.org/r/20200821103407.3362149-1-mpe@ellerman.id.au
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We have smp_ops->cpu_die() and ppc_md.cpu_die(). One of them offlines
the current CPU and one offlines another CPU, can you guess which is
which? Also one is in smp_ops and one is in ppc_md?
So rename ppc_md.cpu_die(), to cpu_offline_self(), because that's what
it does. And move it into smp_ops where it belongs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015634.1974478-3-mpe@ellerman.id.au
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Avoid the eternal confusion between cpu_die() and __cpu_die() by
removing the former, folding it into its only caller.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015634.1974478-2-mpe@ellerman.id.au
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arch_cpu_idle_dead() is in idle.c, which makes sense, but it's inside
a CONFIG_HOTPLUG_CPU block.
It would be more at home in smp.c, inside the existing
CONFIG_HOTPLUG_CPU block. Note that CONFIG_HOTPLUG_CPU depends on
CONFIG_SMP so even though smp.c is not built for SMP=n builds, that's
fine.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015634.1974478-1-mpe@ellerman.id.au
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Sparse warns about all the init functions:
symbol init_ppc970_pmu was not declared. Should it be static?
symbol init_power5p_pmu was not declared. Should it be static?
symbol init_power5_pmu was not declared. Should it be static?
symbol init_power6_pmu was not declared. Should it be static?
symbol init_power7_pmu was not declared. Should it be static?
symbol init_power9_pmu was not declared. Should it be static?
symbol init_power8_pmu was not declared. Should it be static?
symbol init_generic_compat_pmu was not declared. Should it be static?
They're already declared in internal.h, so just make sure all the C
files include that directly or indirectly.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://lore.kernel.org/r/20200916115637.3100484-2-mpe@ellerman.id.au
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Sparse says:
symbol slb_setup_new_exec was not declared. Should it be static?
No, it should have a declaration in a header, add one.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916115637.3100484-1-mpe@ellerman.id.au
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Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code.
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200916025026.3992835-1-liushixin2@huawei.com
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Fix link error when CONFIG_PPC_RADIX_MMU is disabled:
powerpc64-linux-gnu-ld: arch/powerpc/platforms/pseries/lpar.o:(.toc+0x0): undefined reference to `mmu_pid_bits'
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200917020643.90375-1-yangyingliang@huawei.com
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Merge Nick's series to add ARCH_WANT_IRQS_OFF_ACTIVATE_MM.
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Clang, and GCC with -Wmaybe-uninitialized, can't see that val is
unused in get_fpexec_mode():
arch/powerpc/kernel/process.c:1940:7: error: variable 'val' is used
uninitialized whenever 'if' condition is true
if (cpu_has_feature(CPU_FTR_SPE)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
We know that CPU_FTR_SPE will only be true iff CONFIG_SPE is also
true, but the compiler doesn't.
Avoid it by initialising val to zero.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 532ed1900d37 ("powerpc/process: Remove useless #ifdef CONFIG_SPE")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20200917024509.3253837-1-mpe@ellerman.id.au
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From Srikar's cover letter, with some reformatting:
Cleanup of existing powerpc topologies and add coregroup support on
powerpc. Coregroup is a group of (subset of) cores of a DIE that share
a resource.
Summary of some of the testing done with coregroup patchset.
It includes ebizzy, schbench, perf bench sched pipe and topology
verification. On the left side are results from powerpc/next tree and
on the right are the results with the patchset applied. Topological
verification clearly shows that there is no change in topology with
and without the patches on all the 3 class of systems that were
tested.
Power 9 PowerNV (2 Node/ 160 Cpu System)
----------------------------------------
Baseline Baseline + Coregroup Support
N Min Max Median Avg Stddev N Min Max Median Avg Stddev
100 993884 1276090 1173476 1165914 54867.201 100 910470 1279820 1171095 1162091 67363.28
^ ebizzy (Throughput of 100 iterations of 30 seconds higher throughput is better)
schbench (latency hence lower is better)
Latency percentiles (usec) Latency percentiles (usec)
50.0th: 455 50.0th: 454
75.0th: 533 75.0th: 543
90.0th: 683 90.0th: 701
95.0th: 743 95.0th: 737
*99.0th: 815 *99.0th: 805
99.5th: 839 99.5th: 835
99.9th: 913 99.9th: 893
min=0, max=1011 min=0, max=2833
perf bench sched pipe (lesser time and higher ops/sec is better)
Running 'sched/pipe' benchmark: Running 'sched/pipe' benchmark:
Executed 1000000 pipe operations between two processes Executed 1000000 pipe operations between two processes
Total time: 6.083 [sec] Total time: 6.303 [sec]
6.083576 usecs/op 6.303318 usecs/op
164377 ops/sec 158646 ops/sec
Power 9 LPAR (2 Node/ 128 Cpu System)
-------------------------------------
Baseline Baseline + Coregroup Support
N Min Max Median Avg Stddev N Min Max Median Avg Stddev
100 1058029 1295393 1200414 1188306.7 56786.538 100 943264 1287619 1180522 1168473.2 64469.955
^ ebizzy (Throughput of 100 iterations of 30 seconds higher throughput is better)
schbench (latency hence lower is better)
Latency percentiles (usec) Latency percentiles (usec)
50.0000th: 34 50.0000th: 39
75.0000th: 46 75.0000th: 52
90.0000th: 53 90.0000th: 68
95.0000th: 56 95.0000th: 77
*99.0000th: 61 *99.0000th: 89
99.5000th: 63 99.5000th: 94
99.9000th: 81 99.9000th: 169
min=0, max=8405 min=0, max=23674
perf bench sched pipe (lesser time and higher ops/sec is better)
Running 'sched/pipe' benchmark: Running 'sched/pipe' benchmark:
Executed 1000000 pipe operations between two processes Executed 1000000 pipe operations between two processes
Total time: 8.768 [sec] Total time: 5.217 [sec]
8.768400 usecs/op 5.217625 usecs/op
114045 ops/sec 191658 ops/sec
Power 8 LPAR (8 Node/ 256 Cpu System)
-------------------------------------
Baseline Baseline + Coregroup Support
N Min Max Median Avg Stddev N Min Max Median Avg Stddev
100 1267615 1965234 1707423 1689137.6 144363.29 100 1175357 1924262 1691104 1664792.1 145876.4
^ ebizzy (Throughput of 100 iterations of 30 seconds higher throughput is better)
schbench (latency hence lower is better)
Latency percentiles (usec) Latency percentiles (usec)
50.0th: 37 50.0th: 36
75.0th: 51 75.0th: 48
90.0th: 59 90.0th: 55
95.0th: 63 95.0th: 59
*99.0th: 71 *99.0th: 67
99.5th: 75 99.5th: 72
99.9th: 105 99.9th: 170
min=0, max=18560 min=0, max=27031
perf bench sched pipe (lesser time and higher ops/sec is better)
Running 'sched/pipe' benchmark: Running 'sched/pipe' benchmark:
Executed 1000000 pipe operations between two processes Executed 1000000 pipe operations between two processes
Total time: 6.013 [sec] Total time: 5.930 [sec]
6.013963 usecs/op 5.930724 usecs/op
166279 ops/sec 168613 ops/sec
Topology verification on Power9
Power9 / powernv / SMT4
$ tail /proc/cpuinfo
cpu : POWER9, altivec supported
clock : 3600.000000MHz
revision : 2.2 (pvr 004e 1202)
timebase : 512000000
platform : PowerNV
model : 9006-22P
machine : PowerNV 9006-22P
firmware : OPAL
MMU : Radix
Baseline Baseline + Coregroup Support
lscpu lscpu
------ ------
Architecture: ppc64le Architecture: ppc64le
Byte Order: Little Endian Byte Order: Little Endian
CPU(s): 160 CPU(s): 160
On-line CPU(s) list: 0-159 On-line CPU(s) list: 0-159
Thread(s) per core: 4 Thread(s) per core: 4
Core(s) per socket: 20 Core(s) per socket: 20
Socket(s): 2 Socket(s): 2
NUMA node(s): 2 NUMA node(s): 2
Model: 2.2 (pvr 004e 1202) Model: 2.2 (pvr 004e 1202)
Model name: POWER9, altivec supported Model name: POWER9, altivec supported
CPU max MHz: 3800.0000 CPU max MHz: 3800.0000
CPU min MHz: 2166.0000 CPU min MHz: 2166.0000
L1d cache: 32K L1d cache: 32K
L1i cache: 32K L1i cache: 32K
L2 cache: 512K L2 cache: 512K
L3 cache: 10240K L3 cache: 10240K
NUMA node0 CPU(s): 0-79 NUMA node0 CPU(s): 0-79
NUMA node8 CPU(s): 80-159 NUMA node8 CPU(s): 80-159
grep . /proc/sys/kernel/sched_domain/cpu0/domain*/name grep . /proc/sys/kernel/sched_domain/cpu0/domain*/name
----------------------------------------------------- -----------------------------------------------------
/proc/sys/kernel/sched_domain/cpu0/domain0/name:SMT /proc/sys/kernel/sched_domain/cpu0/domain0/name:SMT
/proc/sys/kernel/sched_domain/cpu0/domain1/name:CACHE /proc/sys/kernel/sched_domain/cpu0/domain1/name:CACHE
/proc/sys/kernel/sched_domain/cpu0/domain2/name:DIE /proc/sys/kernel/sched_domain/cpu0/domain2/name:DIE
/proc/sys/kernel/sched_domain/cpu0/domain3/name:NUMA /proc/sys/kernel/sched_domain/cpu0/domain3/name:NUMA
grep . /proc/sys/kernel/sched_domain/cpu0/domain*/flags grep . /proc/sys/kernel/sched_domain/cpu0/domain*/flags
------------------------------------------------------ ------------------------------------------------------
/proc/sys/kernel/sched_domain/cpu0/domain0/flags:2391 /proc/sys/kernel/sched_domain/cpu0/domain0/flags:2391
/proc/sys/kernel/sched_domain/cpu0/domain1/flags:2327 /proc/sys/kernel/sched_domain/cpu0/domain1/flags:2327
/proc/sys/kernel/sched_domain/cpu0/domain2/flags:2071 /proc/sys/kernel/sched_domain/cpu0/domain2/flags:2071
/proc/sys/kernel/sched_domain/cpu0/domain3/flags:12801 /proc/sys/kernel/sched_domain/cpu0/domain3/flags:12801
Baseline
head /proc/schedstat
--------------------
version 15
timestamp 4295043536
cpu0 0 0 0 0 0 0 9597119314 2408913694 11897
domain0 00000000,00000000,00000000,00000000,0000000f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,0000ffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 ffffffff,ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 4941435230 11106132 1583
domain0 00000000,00000000,00000000,00000000,0000000f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Baseline + Coregroup Support
head /proc/schedstat
--------------------
version 15
timestamp 4296311826
cpu0 0 0 0 0 0 0 3353674045024 3781680865826 297483
domain0 00000000,00000000,00000000,00000000,0000000f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,0000ffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 ffffffff,ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 3337873293332 4231590033856 229090
domain0 00000000,00000000,00000000,00000000,0000000f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Post sudo ppc64_cpu --smt=1 Post sudo ppc64_cpu --smt=1
--------------------- ---------------------
grep . /proc/sys/kernel/sched_domain/cpu0/domain*/name grep . /proc/sys/kernel/sched_domain/cpu0/domain*/name
----------------------------------------------------- -----------------------------------------------------
/proc/sys/kernel/sched_domain/cpu0/domain0/name:CACHE /proc/sys/kernel/sched_domain/cpu0/domain0/name:CACHE
/proc/sys/kernel/sched_domain/cpu0/domain1/name:DIE /proc/sys/kernel/sched_domain/cpu0/domain1/name:DIE
/proc/sys/kernel/sched_domain/cpu0/domain2/name:NUMA /proc/sys/kernel/sched_domain/cpu0/domain2/name:NUMA
grep . /proc/sys/kernel/sched_domain/cpu0/domain*/flags grep . /proc/sys/kernel/sched_domain/cpu0/domain*/flags
------------------------------------------------------ ------------------------------------------------------
/proc/sys/kernel/sched_domain/cpu0/domain0/flags:2327 /proc/sys/kernel/sched_domain/cpu0/domain0/flags:2327
/proc/sys/kernel/sched_domain/cpu0/domain1/flags:2071 /proc/sys/kernel/sched_domain/cpu0/domain1/flags:2071
/proc/sys/kernel/sched_domain/cpu0/domain2/flags:12801 /proc/sys/kernel/sched_domain/cpu0/domain2/flags:12801
Baseline:
head /proc/schedstat
--------------------
version 15
timestamp 4295046242
cpu0 0 0 0 0 0 0 10978610020 2658997390 13068
domain0 00000000,00000000,00000000,00000000,00000011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00001111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 91111111,11111111,11111111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu4 0 0 0 0 0 0 5408663896 95701034 7697
domain0 00000000,00000000,00000000,00000000,00000011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00001111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 91111111,11111111,11111111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Baseline + Coregroup Support
head /proc/schedstat
--------------------
version 15
timestamp 4296314905
cpu0 0 0 0 0 0 0 3355392013536 3781975150576 298723
domain0 00000000,00000000,00000000,00000000,00000011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00001111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 91111111,11111111,11111111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu4 0 0 0 0 0 0 3351637920996 4427329763050 256776
domain0 00000000,00000000,00000000,00000000,00000011 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00001111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 91111111,11111111,11111111,11111111,11111111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Similar verification was done on Power 8 (8 Node 256 CPU LPAR) and
Power 9 (2 node 128 Cpu LPAR) and they showed the topology before and
after the patch to be identical. If Interested, I could provide the
same.
On Power 9 (with device-tree enablement to show coregroups):
$ tail /proc/cpuinfo
processor : 127
cpu : POWER9 (architected), altivec supported
clock : 3000.000000MHz
revision : 2.2 (pvr 004e 0202)
timebase : 512000000
platform : pSeries
model : IBM,9008-22L
machine : CHRP IBM,9008-22L
MMU : Hash
Before patchset:
$ cat /proc/sys/kernel/sched_domain/cpu0/domain*/name
SMT
CACHE
DIE
NUMA
$ head /proc/schedstat
version 15
timestamp 4318242208
cpu0 0 0 0 0 0 0 28077107004 4773387362 78205
domain0 00000000,00000000,00000000,00000055 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 24177439200 413887604 75393
domain0 00000000,00000000,00000000,000000aa 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
After patchset:
$ cat /proc/sys/kernel/sched_domain/cpu0/domain*/name
SMT
CACHE
MC
DIE
NUMA
$ head /proc/schedstat
version 15
timestamp 4318242208
cpu0 0 0 0 0 0 0 28077107004 4773387362 78205
domain0 00000000,00000000,00000000,00000055 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain1 00000000,00000000,00000000,000000ff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain2 00000000,00000000,00000000,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain3 00000000,00000000,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
domain4 ffffffff,ffffffff,ffffffff,ffffffff 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
cpu1 0 0 0 0 0 0 24177439200 413887604 75393
domain0 00000000,00000000,00000000,000000aa 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
|
|
Lookup the coregroup id from the associativity array.
If unable to detect the coregroup id, fallback on the core id.
This way, ensure sched_domain degenerates and an extra sched domain is
not created.
Ideally this function should have been implemented in
arch/powerpc/kernel/smp.c. However if its implemented in mm/numa.c, we
don't need to find the primary domain again.
If the device-tree mentions more than one coregroup, then kernel
implements only the last or the smallest coregroup, which currently
corresponds to the penultimate domain in the device-tree.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-11-srikar@linux.vnet.ibm.com
|
|
Add percpu coregroup maps and masks to create coregroup domain.
If a coregroup doesn't exist, the coregroup domain will be degenerated
in favour of SMT/CACHE domain. Do note this patch is only creating stubs
for cpu_to_coregroup_id. The actual cpu_to_coregroup_id implementation
would be in a subsequent patch.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-10-srikar@linux.vnet.ibm.com
|
|
If allocated earlier and the search fails, then cpu_l1_cache_map cpumask
is unnecessarily cleared. However cpu_l1_cache_map can be allocated /
cleared after we search thread group.
Please note CONFIG_CPUMASK_OFFSTACK is not set on Powerpc. Hence cpumask
allocated by zalloc_cpumask_var_node is never freed.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-9-srikar@linux.vnet.ibm.com
|
|
Add support for grouping cores based on the device-tree classification.
- The last domain in the associativity domains always refers to the
core.
- If primary reference domain happens to be the penultimate domain in
the associativity domains device-tree property, then there are no
coregroups. However if its not a penultimate domain, then there are
coregroups. There can be more than one coregroup. For now we would be
interested in the last or the smallest coregroups, i.e one sub-group
per DIE.
Currently there are no firmwares that are exposing this grouping. Hence
allow the basis for grouping to be abstract. Once the firmware starts
using this grouping, code would be added to detect the type of grouping
and adjust the sd domain flags accordingly.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-8-srikar@linux.vnet.ibm.com
|
|
In start_secondary, even if shared_cache was already set, system does a
redundant match for cpumask. This redundant check can be removed by
checking if shared_cache is already set.
While here, localize the sibling_mask variable to within the if
condition.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-7-srikar@linux.vnet.ibm.com
|
|
Current code assumes that cpumask of cpus sharing a l2-cache mask will
always be a superset of cpu_sibling_mask.
Lets stop that assumption. cpu_l2_cache_mask is a superset of
cpu_sibling_mask if and only if shared_caches is set.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200913171038.GB11808@linux.vnet.ibm.com
|
|
Move topology fixup based on the platform attributes into its own
function which is called just before set_sched_topology.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-5-srikar@linux.vnet.ibm.com
|
|
Just moving the powerpc_topology description above.
This will help in using functions in this file and avoid declarations.
No other functional changes
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-4-srikar@linux.vnet.ibm.com
|
|
A new sched_domain_topology_level was added just for Power9. However the
same can be achieved by merging powerpc_topology with power9_topology
and makes the code more simpler especially when adding a new sched
domain.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-3-srikar@linux.vnet.ibm.com
|
|
Fix a build warning in a non CONFIG_NEED_MULTIPLE_NODES
"error: _numa_cpu_lookup_table_ undeclared"
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-2-srikar@linux.vnet.ibm.com
|
|
Currently Linux kernel with CONFIG_NUMA on a system with multiple
possible nodes, marks node 0 as online at boot. However in practice,
there are systems which have node 0 as memoryless and cpuless.
This can cause numa_balancing to be enabled on systems with only one node
with memory and CPUs. The existence of this dummy node which is cpuless and
memoryless node can confuse users/scripts looking at output of lscpu /
numactl.
By marking, node 0 as offline, lets stop assuming that node 0 is
always online. If node 0 has CPU or memory that are online, node 0 will
again be set as online.
v5.8
available: 2 nodes (0,2)
node 0 cpus:
node 0 size: 0 MB
node 0 free: 0 MB
node 2 cpus: 0 1 2 3 4 5 6 7
node 2 size: 32625 MB
node 2 free: 31490 MB
node distances:
node 0 2
0: 10 20
2: 20 10
proc and sys files
------------------
/sys/devices/system/node/online: 0,2
/proc/sys/kernel/numa_balancing: 1
/sys/devices/system/node/has_cpu: 2
/sys/devices/system/node/has_memory: 2
/sys/devices/system/node/has_normal_memory: 2
/sys/devices/system/node/possible: 0-31
v5.8 + patch
------------------
available: 1 nodes (2)
node 2 cpus: 0 1 2 3 4 5 6 7
node 2 size: 32625 MB
node 2 free: 31487 MB
node distances:
node 2
2: 10
proc and sys files
------------------
/sys/devices/system/node/online: 2
/proc/sys/kernel/numa_balancing: 0
/sys/devices/system/node/has_cpu: 2
/sys/devices/system/node/has_memory: 2
/sys/devices/system/node/has_normal_memory: 2
/sys/devices/system/node/possible: 0-31
Example of a node with online CPUs/memory on node 0.
(Same o/p with and without patch)
numactl -H
available: 4 nodes (0-3)
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
node 0 size: 32482 MB
node 0 free: 22994 MB
node 1 cpus: 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
node 1 size: 0 MB
node 1 free: 0 MB
node 2 cpus: 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
node 2 size: 0 MB
node 2 free: 0 MB
node 3 cpus: 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 node 3 size: 0 MB
node 3 free: 0 MB
node distances:
node 0 1 2 3
0: 10 20 40 40
1: 20 10 40 40
2: 40 40 10 20
3: 40 40 20 10
Note: On Powerpc, cpu_to_node of possible but not present cpus would
previously return 0. Hence this commit depends on commit ("powerpc/numa: Set
numa_node for all possible cpus") and commit ("powerpc/numa: Prefer node id
queried from vphn"). Without the 2 commits, Powerpc system might crash.
1. User space applications like Numactl, lscpu, that parse the sysfs tend to
believe there is an extra online node. This tends to confuse users and
applications. Other user space applications start believing that system was
not able to use all the resources (i.e missing resources) or the system was
not setup correctly.
2. Also existence of dummy node also leads to inconsistent information. The
number of online nodes is inconsistent with the information in the
device-tree and resource-dump
3. When the dummy node is present, single node non-Numa systems end up showing
up as NUMA systems and numa_balancing gets enabled. This will mean we take
the hit from the unnecessary numa hinting faults.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818081104.57888-4-srikar@linux.vnet.ibm.com
|
|
Node id queried from the static device tree may not
be correct. For example: it may always show 0 on a shared processor.
Hence prefer the node id queried from vphn and fallback on the device tree
based node id if vphn query fails.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818081104.57888-3-srikar@linux.vnet.ibm.com
|
|
A Powerpc system with multiple possible nodes and with CONFIG_NUMA
enabled always used to have a node 0, even if node 0 does not any cpus
or memory attached to it. As per PAPR, node affinity of a cpu is only
available once its present / online. For all cpus that are possible but
not present, cpu_to_node() would point to node 0.
To ensure a cpuless, memoryless dummy node is not online, powerpc need
to make sure all possible but not present cpu_to_node are set to a
proper node.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200818081104.57888-2-srikar@linux.vnet.ibm.com
|
|
As per draft LoPAPR (Revision 2.9_pre7), section B.5.3 "Run Time
Abstraction Services (RTAS) Node" available at:
https://openpowerfoundation.org/wp-content/uploads/2020/07/LoPAR-20200611.pdf
... there are 2 device tree properties:
"ibm,max-associativity-domains"
which defines the maximum number of domains that the firmware i.e
PowerVM can support.
and:
"ibm,current-associativity-domains"
which defines the maximum number of domains that the current
platform can support.
The value of "ibm,max-associativity-domains" is always greater than or
equal to "ibm,current-associativity-domains" property. If the latter
property is not available, use "ibm,max-associativity-domain" as a
fallback. In this yet to be released LoPAPR, "ibm,current-associativity-domains"
is mentioned in page 833 / B.5.3 which is covered under under
"Appendix B. System Binding" section
Currently powerpc uses the "ibm,max-associativity-domains" property
while setting the possible number of nodes. This is currently set at
32. However the possible number of nodes for a platform may be
significantly less. Hence set the possible number of nodes based on
"ibm,current-associativity-domains" property.
Nathan Lynch had raised a valid concern that post LPM (Live Partition
Migration), a user could DLPAR add processors and memory after LPM
with "new" associativity properties:
https://lore.kernel.org/linuxppc-dev/871rljfet9.fsf@linux.ibm.com/t/#u
He also pointed out that "ibm,max-associativity-domains" has the same
contents on all currently available PowerVM systems, unlike
"ibm,current-associativity-domains" and hence may be better able to
handle the new NUMA associativity properties.
However with the recent commit dbce45628085 ("powerpc/numa: Limit
possible nodes to within num_possible_nodes"), all new NUMA
associativity properties are capped to initially set nr_node_ids.
Hence this commit should be safe with any new DLPAR add post LPM.
$ lsprop /proc/device-tree/rtas/ibm,*associ*-domains
/proc/device-tree/rtas/ibm,current-associativity-domains
00000005 00000001 00000002 00000002 00000002 00000010
/proc/device-tree/rtas/ibm,max-associativity-domains
00000005 00000001 00000008 00000020 00000020 00000100
$ cat /sys/devices/system/node/possible ##Before patch
0-31
$ cat /sys/devices/system/node/possible ##After patch
0-1
Note the maximum nodes this platform can support is only 2 but the
possible nodes is set to 32.
This is important because lot of kernel and user space code allocate
structures for all possible nodes leading to a lot of memory that is
allocated but not used.
I ran a simple experiment to create and destroy 100 memory cgroups on
boot on a 8 node machine (Power8 Alpine).
Before patch:
free -k at boot
total used free shared buff/cache available
Mem: 523498176 4106816 518820608 22272 570752 516606720
Swap: 4194240 0 4194240
free -k after creating 100 memory cgroups
total used free shared buff/cache available
Mem: 523498176 4628416 518246464 22336 623296 516058688
Swap: 4194240 0 4194240
free -k after destroying 100 memory cgroups
total used free shared buff/cache available
Mem: 523498176 4697408 518173760 22400 627008 515987904
Swap: 4194240 0 4194240
After patch:
free -k at boot
total used free shared buff/cache available
Mem: 523498176 3969472 518933888 22272 594816 516731776
Swap: 4194240 0 4194240
free -k after creating 100 memory cgroups
total used free shared buff/cache available
Mem: 523498176 4181888 518676096 22208 640192 516496448
Swap: 4194240 0 4194240
free -k after destroying 100 memory cgroups
total used free shared buff/cache available
Mem: 523498176 4232320 518619904 22272 645952 516443264
Swap: 4194240 0 4194240
Observations:
Fixed kernel takes 137344 kb (4106816-3969472) less to boot.
Fixed kernel takes 309184 kb (4628416-4181888-137344) less to create 100 memcgs.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[mpe: Reformat change log a bit for readability]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200817055257.110873-1-srikar@linux.vnet.ibm.com
|
|
On Power9, a pair of SMT4 cores can be presented by the firmware as a SMT8
core for backward compatibility reasons, with the fusion of two SMT4 cores.
Powerpc allows LPARs to be live migrated from Power8 to Power9. Existing
software developed/configured for Power8, expects to see a SMT8 core.
In order to maintain userspace backward compatibility (with Power8 chips in
case of Power9) in enterprise Linux systems, the topology_sibling_cpumask
has to be set to SMT8 core.
cpu_smt_mask() should generally point to the cpu mask of the SMT4 core.
Hence override the default cpu_smt_mask() to be powerpc specific
allowing for better scheduling behaviour on Power.
schbench
(latency measured in usecs, so lesser is better)
Without patch With patch
Latency percentiles (usec) Latency percentiles (usec)
50.0000th: 34 50.0000th: 38
75.0000th: 47 75.0000th: 52
90.0000th: 54 90.0000th: 60
95.0000th: 57 95.0000th: 64
*99.0000th: 62 *99.0000th: 72
99.5000th: 65 99.5000th: 75
99.9000th: 76 99.9000th: 3452
min=0, max=9205 min=0, max=9344
schbench (With Cede disabled)
Without patch With patch
Latency percentiles (usec) Latency percentiles (usec)
50.0000th: 20 50.0000th: 21
75.0000th: 28 75.0000th: 29
90.0000th: 33 90.0000th: 34
95.0000th: 35 95.0000th: 37
*99.0000th: 40 *99.0000th: 40
99.5000th: 48 99.5000th: 42
99.9000th: 94 99.9000th: 79
min=0, max=791 min=0, max=791
perf bench sched pipe
usec/ops : lesser is better
Without patch
N Min Max Median Avg Stddev
101 5.095113 5.595269 5.204842 5.2298776 0.10762713
5.10 - 5.15 : ################################################## 23% (24)
5.15 - 5.20 : ############################################# 21% (22)
5.20 - 5.25 : ################################################## 23% (24)
5.25 - 5.30 : ######################### 11% (12)
5.30 - 5.35 : ########## 4% (5)
5.35 - 5.40 : ######## 3% (4)
5.40 - 5.45 : ######## 3% (4)
5.45 - 5.50 : #### 1% (2)
5.50 - 5.55 : ## 0% (1)
5.55 - 5.60 : #### 1% (2)
With patch
N Min Max Median Avg Stddev
101 5.134675 8.524719 5.207658 5.2780985 0.34911969
5.1 - 5.5 : ################################################## 94% (95)
5.5 - 5.8 : ## 3% (4)
5.8 - 6.2 : 0% (1)
6.2 - 6.5 :
6.5 - 6.8 :
6.8 - 7.2 :
7.2 - 7.5 :
7.5 - 7.8 :
7.8 - 8.2 :
8.2 - 8.5 :
perf bench sched pipe (cede disabled)
usec/ops : lesser is better
Without patch
N Min Max Median Avg Stddev
101 7.884227 12.576538 7.956474 8.0170722 0.46159054
7.9 - 8.4 : ################################################## 99% (100)
8.4 - 8.8 :
8.8 - 9.3 :
9.3 - 9.8 :
9.8 - 10.2 :
10.2 - 10.7 :
10.7 - 11.2 :
11.2 - 11.6 :
11.6 - 12.1 :
12.1 - 12.6 :
With patch
N Min Max Median Avg Stddev
101 7.956021 8.217284 8.015615 8.0283866 0.049844967
7.96 - 7.98 : ###################### 12% (13)
7.98 - 8.01 : ################################################## 28% (29)
8.01 - 8.03 : #################################### 20% (21)
8.03 - 8.06 : ######################### 14% (15)
8.06 - 8.09 : ###################### 12% (13)
8.09 - 8.11 : ###### 3% (4)
8.11 - 8.14 : ### 1% (2)
8.14 - 8.17 : ### 1% (2)
8.17 - 8.19 :
8.19 - 8.22 : # 0% (1)
Observations: With the patch, the initial run/iteration takes a slight
longer time. This can be attributed to the fact that now we pick a CPU
from a idle core which could be sleep mode. Once we remove the cede,
state the numbers improve in favour of the patch.
ebizzy:
transactions per second (higher is better)
without patch
N Min Max Median Avg Stddev
100 1018433 1304470 1193208 1182315.7 60018.733
1018433 - 1047037 : ###### 3% (3)
1047037 - 1075640 : ######## 4% (4)
1075640 - 1104244 : ######## 4% (4)
1104244 - 1132848 : ############### 7% (7)
1132848 - 1161452 : #################################### 17% (17)
1161452 - 1190055 : ########################## 12% (12)
1190055 - 1218659 : ############################################# 21% (21)
1218659 - 1247263 : ################################################## 23% (23)
1247263 - 1275866 : ######## 4% (4)
1275866 - 1304470 : ######## 4% (4)
with patch
N Min Max Median Avg Stddev
100 967014 1292938 1208819 1185281.8 69815.851
967014 - 999606 : ## 1% (1)
999606 - 1032199 : ## 1% (1)
1032199 - 1064791 : ############ 6% (6)
1064791 - 1097384 : ########## 5% (5)
1097384 - 1129976 : ################## 9% (9)
1129976 - 1162568 : #################### 10% (10)
1162568 - 1195161 : ########################## 13% (13)
1195161 - 1227753 : ############################################ 22% (22)
1227753 - 1260346 : ################################################## 25% (25)
1260346 - 1292938 : ############## 7% (7)
Observations: Not much changes, ebizzy is not much impacted.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200807074517.27957-2-srikar@linux.vnet.ibm.com
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cpu_smt_mask tracks topology_sibling_cpumask. This would be good for
most architectures. One of the users of cpu_smt_mask(), would be to
identify idle-cores. On Power9, a pair of SMT4 cores can be presented
by the firmware as a SMT8 core for backward compatibility reasons.
powerpc allows LPARs to be live migrated from Power8 to Power9. Do
note Power8 had only SMT8 cores. Existing software which has been
developed/configured for Power8 would expect to see SMT8 core.
Maintaining the illusion of SMT8 core is a requirement to make that
work.
In order to maintain above userspace backward compatibility with
previous versions of processor, Power9 onwards there is option to the
firmware to advertise a pair of SMT4 cores as a fused cores aka SMT8
core. On Power9 this pair shares the L2 cache as well. However, from
the scheduler's point of view, a core should be determined by SMT4,
since its a completely independent unit of compute. Hence allow
powerpc architecture to override the default cpu_smt_mask() to point
to the SMT4 cores in a SMT8 mode.
This will ensure the scheduler is always given the right information.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200807074517.27957-1-srikar@linux.vnet.ibm.com
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Make kernel with `C=2`:
drivers/macintosh/smu.c:1018:30: warning: symbol
'__smu_get_sdb_partition' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914122615.65669-1-wangwensheng4@huawei.com
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A warning is reported by the kernel in case perf_stats_show() returns
an error code. The warning is of the form below:
papr_scm ibm,persistent-memory:ibm,pmemory@44100001:
Failed to query performance stats, Err:-10
dev_attr_show: perf_stats_show+0x0/0x1c0 [papr_scm] returned bad count
fill_read_buffer: dev_attr_show+0x0/0xb0 returned bad count
On investigation it looks like that the compiler is silently
truncating the return value of drc_pmem_query_stats() from 'long' to
'int', since the variable used to store the return code 'rc' is an
'int'. This truncated value is then returned back as a 'ssize_t' back
from perf_stats_show() to 'dev_attr_show()' which thinks of it as a
large unsigned number and triggers this warning..
To fix this we update the type of variable 'rc' from 'int' to
'ssize_t' that prevents the compiler from truncating the return value
of drc_pmem_query_stats() and returning correct signed value back from
perf_stats_show().
Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200912081451.66225-1-vaibhav@linux.ibm.com
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Commit 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of
single-threaded mm_cpumask") added a mechanism to trim the mm_cpumask of
a process under certain conditions. One of the assumptions is that
mm_users would not be incremented via a reference outside the process
context with mmget_not_zero() then go on to kthread_use_mm() via that
reference.
That invariant was broken by io_uring code (see previous sparc64 fix),
but I'll point Fixes: to the original powerpc commit because we are
changing that assumption going forward, so this will make backports
match up.
Fix this by no longer relying on that assumption, but by having each CPU
check the mm is not being used, and clearing their own bit from the mask
only if it hasn't been switched-to by the time the IPI is processed.
This relies on commit 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB
invalidate") and ARCH_WANT_IRQS_OFF_ACTIVATE_MM to disable irqs over mm
switch sequences.
Fixes: 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Depends-on: 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB invalidate")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914045219.3736466-5-npiggin@gmail.com
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